Question

我正在使用XMLReader和SimpleXML的组合，而且，由于我在阅读XML时使用PHP非常新，我想知道为什么第一行（注释掉的）2行代码没有返回任何内容？第二个版本（在注释中注明）确实返回结果。

返回的错误是：

XPath query failed for bio

所以，我不确定失败是在xmlreader代码还是xpath变量中。

感谢任何线索。

PHP：

<?php
$secondary_user_id = "jsmith";

$url_bio = "bio_short.xml";

$reader = new XMLReader();
//load the selected XML file to the DOM 
$reader->open($url_bio);

while ($reader->read()) 
{

// 'property' in the line below is the name of our main XML node  
if ($reader->nodeType == XMLReader::ELEMENT && $reader->name == 'Users') 
    {
                //begin - 1st version with DOMDocument
            //$doc = new DOMDocument('1.0','UTF-8');//
            //$xml_bio_report = simplexml_import_dom($doc->importNode($reader->expand(),true));//
            //end - 1st version             
            //begin - 2nd version with SimpleXMLElement 
            $xml_bio_report = new SimpleXMLElement($reader->readOuterXML());
            //end - 2nd version

            $xml_bio_report->registerXPathNamespace('xlink','http://www.w3.org/1999/xlink');
            $xml_bio_report->registerXPathNamespace('dmu','http://www.digitalmeasures.com/schema/user-metadata');

              //echo $xml_bio_report->Users->User;


            $xml_bio_report_abbrev = $xml_bio_report->xpath('//User[@SecondaryID="'.$secondary_user_id.'"]');

            if ($xml_bio_report_abbrev){
                echo '<h1>'.$xml_bio_report_abbrev[0]['username'].'</h1>';
                echo '<h1>'.$xml_bio_report_abbrev[0]['SecondaryID'].'</h1>';

                $user_name = $xml_bio_report_abbrev[0]['username'];
                $secondary_id = $xml_bio_report_abbrev[0]['SecondaryID'];
                //var_dump($xml_bio_report_abbrev);
            } else {
                echo 'XPath query failed for bio';  
            }

            $user_name=trim($user_name);
            echo "user_name is...".$user_name."<br>";
            echo "secondary_id is...".$secondary_id."<br>";

    }
}
?>

XML（＆＃39; bio_short.xml＆＃39;）：

<?xml version="1.0" encoding="UTF-8"?>
<Users xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:dmu="http://www.digitalmeasures.com/schema/user-metadata">
    <User username="john-smith" dmu:userId="14" SecondaryID="jsmith" enabled="false">
        <FirstName>John</FirstName>
        <MiddleName>L</MiddleName>
        <LastName>Smith</LastName>
        <Email>john-smith@email.com</Email>
        <LocalAuthentication/>
        <Item xlink:type="simple" xlink:href="/login/service/v4/User/USERNAME:john-smith"/>
    </User>
    <User username="mary-smith" dmu:userId="19" SecondaryID="msmith">
        <FirstName>Mary</FirstName>
        <LastName>Smith</LastName>
        <Email>mary-smith@email.com</Email>
        <LocalAuthentication/>
        <Item xlink:type="simple" xlink:href="/login/service/v4/User/USERNAME:mary-smith"/>
    </User>   
</Users>

更新：当我重新编写如下代码时，它使用此page作为参考返回结果与复合语句（注释掉）相反，差异是否会从构造变量的顺序产生？

if ($reader->nodeType == XMLReader::ELEMENT && $reader->name == 'Users') 
    {


            $node = $reader->expand();              

            $doc = new DOMDocument('1.0','UTF-8');

            $n = $doc->importNode($node,true);

            $doc->appendChild($n);

            $xml_bio_report =  simplexml_import_dom($n);

            //$xml_bio_report = simplexml_import_dom($doc->importNode($reader->expand(),true));

XMLReader和SimpleXML - DOMDocument No Return

0 个答案: